2006 Suzuki Aerio Brake flupid reservoir cap

SHEILA.MILLER88

2006 SUZUKI AERIO

Brakes problem
2006 Suzuki Aerio 4 cyl Manual

I lost my brake fluid reservoir cap, and Suzuki wants $40 for a new one. I can't find a replacement anywhere else, but it will take over a week to get here. Is there a safe way I can temporarily seal off the reservoir so I can still drive? Can you think of any other places that might carry a replacement?